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>53.1. Introduction</A
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><P
>   <ACRONYM
CLASS="ACRONYM"
>GiST</ACRONYM
> stands for Generalized Search Tree.  It is a
   balanced, tree-structured access method, that acts as a base template in
   which to implement arbitrary indexing schemes. B-trees, R-trees and many
   other indexing schemes can be implemented in <ACRONYM
CLASS="ACRONYM"
>GiST</ACRONYM
>.
 </P
><P
>  One advantage of <ACRONYM
CLASS="ACRONYM"
>GiST</ACRONYM
> is that it allows the development
  of custom data types with the appropriate access methods, by
  an expert in the domain of the data type, rather than a database expert.
 </P
><P
>    Some of the information here is derived from the University of California
    at Berkeley's GiST Indexing Project
    <A
HREF="http://gist.cs.berkeley.edu/"
TARGET="_top"
>web site</A
> and
    Marcel Kornacker's thesis,
    <A
HREF="http://www.sai.msu.su/~megera/postgres/gist/papers/concurrency/access-methods-for-next-generation.pdf.gz"
TARGET="_top"
>    Access Methods for Next-Generation Database Systems</A
>.
    The <ACRONYM
CLASS="ACRONYM"
>GiST</ACRONYM
>
    implementation in <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> is primarily
    maintained by Teodor Sigaev and Oleg Bartunov, and there is more
    information on their
    <A
HREF="http://www.sai.msu.su/~megera/postgres/gist/"
TARGET="_top"
>web site</A
>.
  </P
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